Transcript Study of MODIS Retrieved Improvement of Short-term Total Precipitable Water (TPW)

Study of MODIS
Retrieved
Improvement
of Short-term
Total Precipitable
Water (TPW)
Severe
Weather Forecasting
Data
and their Impact
on
Using
high-resolution
MODIS
SevereSatellite
Weather
Simulations
Data
S.-H. Chen1, A. Chen1, J. Haase2, Z. Zhao1, and F. Vandenberghe3
Department of Land, Air, and Water Resources, University of California, Davis, CA
2 Department of Earth and Atmospheric Sciences, Purdue University, W. Lafayette, IN
3 National Center for Atmospheric Research, Boulder, CO
1
Outline
o Introduction
o Observations
o Experiments and Preliminary Results
o Summary
Introduction
MODIS Data
 Moderate Resolution Imaging Spectroradiometer
 Aboard Terra (2000) and Aqua (2002)
 36 spectral bands: 0.405-14.387 μm
 Resolutions: 250m, 500m, 1000m
 Sun-synchronous polar orbit
 Mean altitude : 705 km (equator)
 Width of swath : 2300 km (Terra), 2330 m (Aqua)
Introduction
Retrieved MODIS Total Precipitalbe Water (TPW) Images
MODIS InfraRed (IR) TPW (cm).
This image shows a 50% retrieval rate.
MODIS near InfraRed (nIR) TPW (cm).
This image shows an 85% retrieval rate.
Observations
MODIS swath & Radiosonde Stations
00Z 01/04/04
Observations
MODIS nIR TPW vs. Radiosonde TPW
Before Correction
After Correction
20
y = 0.1606x - 0.7725
10
0
0
10
20
30
40
-10
50
60
MODIS nIR - Radiosonde TPW (mm)
MODIS nIR - Radiosonde TPW (mm)
20
y = -5E-05x + 9E-06
10
0
0
10
20
30
40
-10
-20
-20
MODIS nIR TPW (mm)
RMS ~ 4 mm
MODIS nIR TPW (mm)
RMS ~ 2.5 mm
50
60
MODIS – Radiosonde vs. Latitude
nIR
IR
30
20
10
0
-50
-40
-30
-20
-10
0
IR-Radisonde TPW (mm)
nIR - Radiosonde TPW (mm)
20
10
0
-50
-40
-30
-10
-10
-20
-20
-30
latitude
Latitude
-20
-10
0
Radiosonde Stations
experiments
Hail and Strong Wind reports
(June 1 and 2 2004)
Severe thunderstorm activity on June 1 and 2, 2004 in Oklahoma,
Texas, Arkansas and Louisiana. (Curtsey Storm Prediction Center
NOAA)
experiments
Model Configuration
(Initial Time: 1800 UTC 1 June 2004)
Weather Research and Forecast Model
18 UTC 1 June – 00 UTC 3 June 2004
Global Reanalysis: AVN 1o x 1o
Domain 1 - 30
km
2 - 10
km
Physic: Purdue microphysics
New Kain-Fritsch
RRTM long wave
Dudhia short wave
YSU PBL
experiments
Hurricane Isidore
(1800 UTC 17 – 0000 UTC 20 Sep 2002)
experiments
Model Configuration
(Initial Time: 1800 UTC 17 Sep 2002)
Weather Research and Forecast Model
18 UTC Sep 17 – 00 UTC Sep 20, 2002
Global Reanalysis: AVN 1o x 1o
Domain 1 - 30
km
2 - 10
km
3 - 3.3 km
Physic: Purdue microphysics
New Kain-Fritsch
RRTM long wave
Dudhia short wave
YSU PBL
Experiments
Before Correction
20
y = 0.1606x - 0.7725Assimilated data
Error
y = -5E-05x + 9E-06
10
CNTL
10
20
MOD
30
40
MODC
50
60
0
0
10
20
Original MODIS nIR TPW
-10
-20
10
None
0
0
MODIS nIR - Radiosonde TPW (mm)
MODIS nIR - Radiosonde TPW (mm)
20
After Correction
RMS ~ 4 mm
40
4 mm
-10
Corrected MODIS
-20 nIR TPW
MODIS nIR TPW (mm)
30
2.5 mm
MODIS nIR TPW (mm)
RMS ~ 2.5 mm
50
60
Isidore
Rainfall (0 - 6h simulation)
Observation
MOD
CNTL
MODC
Isidore
Rainfall (6 - 12h simulation)
Observation
MOD
CNTL
MODC
Isidore
Rainfall (12 – 18h simulation)
Observation
MOD
CNTL
MODC
Isidore
TPW Increment and 850 mb Wind
IMOD
IMODC
Maximum CAPE
ICNTL
IMOD
IMODC
Results - Isidore
Maximum 10-m Wind Speed
Minimum Sea Level Pressure
50
OBS
ICNTL
IMOD
IMODC
-1
Maximum 10-m wind (m s)
Sea Level Pressure (hPa)
1005
995
OBS
985
ICNTL
IMOD
975
IMODC
40
30
20
10
965
0
6
12
18
24
30
Time (hr)
36
42
48
54
0
6
12
18
24
30
Time (hr)
36
42
48
54
Radar Reflectivity - Isidore
(2100 UTC 19 Sep 2002)
Radar Image (HRD,NOAA)
ICNTL
IMOD
IMODC
2-km Vertical Velocity (24h)
ICNTL
IMOD
2-km Vertical Velocity (48h)
ICNTL
IMOD
Summary
o The retrieved MODIS TPW might have biases and the RMS error
is about 2-4 mm, which is comparable with that from global
reanalysis over land.
o Preliminary results show that the assimilation of MODIS
TPW has slightly positive impact on sever weather simulations
(rainfall, storm intensity, etc.).
o The assimilation of MODIS TPW may not be able to improve
“now (i.e., at data assimilation time)” nowcasting but may
have a potential to improve “future (e.g., 12h later)”
nowcasting!